Preprint Article Version 1 Preserved in Portico This version is not peer-reviewed

Morphological and Functional Alterations in the CA1 Pyramidal Neurons of the Rat Hippocampus in the Chronic Phase of the Lithium-Pilocarpine Model of Epilepsy

Version 1 : Received: 21 June 2024 / Approved: 21 June 2024 / Online: 24 June 2024 (04:32:45 CEST)

A peer-reviewed article of this Preprint also exists.

Postnikova, T.Y.; Diespirov, G.P.; Malkin, S.L.; Chernyshev, A.S.; Vylekzhanina, E.N.; Zaitsev, A.V. Morphological and Functional Alterations in the CA1 Pyramidal Neurons of the Rat Hippocampus in the Chronic Phase of the Lithium–Pilocarpine Model of Epilepsy. Int. J. Mol. Sci. 2024, 25, 7568. Postnikova, T.Y.; Diespirov, G.P.; Malkin, S.L.; Chernyshev, A.S.; Vylekzhanina, E.N.; Zaitsev, A.V. Morphological and Functional Alterations in the CA1 Pyramidal Neurons of the Rat Hippocampus in the Chronic Phase of the Lithium–Pilocarpine Model of Epilepsy. Int. J. Mol. Sci. 2024, 25, 7568.

Abstract

Epilepsy is known to cause alterations in neural networks. However, many details of these changes remain poorly understood. The objective of this study was to investigate changes in the properties of hippocampal CA1 pyramidal neurons and their synaptic inputs in a rat lithium-pilocarpine model of epilepsy. In the chronic phase of the model, we found a marked loss of pyramidal neurons in the CA1 area. However, the membrane properties of the neurons remained essentially unal-tered. The results of the electrophysiological and morphological studies indicate that the direct pathway from the entorhinal cortex to CA1 neurons is reinforced in epileptic animals, whereas the inputs to them from CA3 are either unaltered or even diminished. In particular, the dendritic spine density in the str. lacunosum moleculare, where the direct pathway from the entorhinal cortex ter-minates, was found to be 2.5 times higher in epileptic rats than in control rats. Furthermore, the summation of responses upon stimulation of the temporoammonic pathway was enhanced by approximately twofold in epileptic rats. This enhancement is believed to be a significant con-tributing factor to the heightened epileptic activity observed in the entorhinal cortex of epileptic rats using an ex vivo 4-aminopyridine model.

Keywords

temporal lobe epilepsy; 4-aminopyridine model; pyramidal neuron; action potential; ictal discharge

Subject

Biology and Life Sciences, Neuroscience and Neurology

Comments (0)

We encourage comments and feedback from a broad range of readers. See criteria for comments and our Diversity statement.

Leave a public comment
Send a private comment to the author(s)
* All users must log in before leaving a comment
Views 0
Downloads 0
Comments 0


×
Alerts
Notify me about updates to this article or when a peer-reviewed version is published.
We use cookies on our website to ensure you get the best experience.
Read more about our cookies here.